iofunc_ability_check()

Updated: May 06, 2022

Verify that the client has a given resource manager ability

Synopsis:

#include <sys/iofunc.h>

int iofunc_ability_check(
       const resmgr_context_t * const ctp,
       const iofunc_ability_e iofuncability );

Arguments:

ctp
A pointer to a resmgr_context_t structure that the resource-manager library uses to pass context information between functions.
iofuncability
The ID of the resource manager ability that you want to check for; one of the following:
  • IOFUNC_ABILITYID_CHOWN
  • IOFUNC_ABILITYID_DUP
  • IOFUNC_ABILITYID_EXEC
  • IOFUNC_ABILITYID_READ

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The iofunc_ability_check() function verifies that the client has the given resource manager ability. The resource manager library creates the following IDs (shown with the ability name and the corresponding constant):

Ability ID Ability name Description
IOFUNC_ABILITYID_CHOWN iofunc/chown (IOFUNC_ABILITY_CHOWN) Allow the client to set the ownership of files, even if not root
IOFUNC_ABILITYID_DUP iofunc/dup (IOFUNC_ABILITY_DUP) Allow the client to duplicate another process's handle
IOFUNC_ABILITYID_EXEC iofunc/exec (IOFUNC_ABILITY_EXEC) Grant execute access to files and directories that the client wouldn't normally have access to
IOFUNC_ABILITYID_READ iofunc/read (IOFUNC_ABILITY_READ) Allow the client to access files for reading, even if it doesn't have the required permissions

You typically use this function to check for special abilities after a call to iofunc_check_access() indicates that the client doesn't have the appropriate permissions to do an operation. These abilities can reduce the number of process manager abilities (see procmgr_ability()) that a client needs to keep.

Returns:

true if the client has the given ability; false if it doesn't.

Classification:

QNX Neutrino

Safety:  
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes